As an electric tool, such as a battery type drilling tool, which is equipped with a handle portion provided so as to protrude sidewise from a side portion of a generally columnar tool main body, there has been provided a tool whose handle portion is loaded with a battery pack as the power source.
Regarding such a hand-held, battery type electric tool, the following patent document, for example, DE 10 2005 036 449 A1, discloses a technique related to a lock mechanism for fixing a battery pack having three columnar battery cells in position in a battery accommodation space in a handle portion.